All up his family are worth about $3 billion, mostly comprising vast land holdings.

While the pair boast about how they like to keep things simple and lead a normal life they have 25 staff including maids, nannies for their two children, private secretaries, footmen and Mary's lady in waiting Caroline Heering.

All costs of running their glamorous lives were up in 2008, including telephone bills, leasing costs and upkeep required to their home.

The pair spend much of the year touring the world attending sailing championships where Frederik competes and Mary has four golf club memberships at the most exclusive courses in Copenhagen. They also ski in Switzerland every year.

Mary is also known as a keen shopper and is often photographed leaving expensive boutiques.

The couple pay no taxes and their budget does not include the hefty cost of most official visits to countries such as the US, where the pair visited in March, as local taxpayers pick up the tab.

Their official visit to four Australian cities in March 2005 cost taxpayers about $750,000 for couple's luxury accommodation, security and other travel expenses.

This included $102,000 on four interstate flights in an RAAF jet and a five-car cavalcade with police escorts, as well as $62,000 for a reception in Parliament House.